Don't you just hate it when your rotary ruler slips near the end of a cut? That can happen if you don't keep pressure along the length of the ruler as the rotary cutter slides along its side. The result -- wasted fabric -- wasted expensive fabric. There are non-slip dots available, little clear or sandpaper patches with adhesive backings that stick to the underneath side of your rotary rulers. They work pretty well, but they're not a perfect solution. RuleSteady is an excellent alternative,, a device that sits on your ruler and cutting mat while you make a cut. Grab the RuleSteady handle and the ruler isn't going anywhere, and makes me more confident about my cuts.